All I can say is, "Location, location, location."
I've had MerlinVSM-MMe's for three years now. I've tried a few placements in my 12' x 18' room. SPeakers are firing down the long wall. I've pretty much followed the Cardas model and had good success. Then last night I had a strong intuition that if I move each speaker back around 2" and closer to the side wall by about 1", it would lock them in better than where I had them. All I can say is that I have some darn good intuition, if I do say so myself. Everything changed for the better especially bass tone and volume. The soundstage opened up considerably. I was so thrilled that I went though several hours of listening to confirm and enjoy the dramatic improvement. I'm not exaggerating. Sounds like I got a new component.
I suspect lots of folks don't have their speakers placed optimally. What a shame because until speakers are really locked in, they're not going to sing to their full potential. Seems like the Merlins are particularly rewarding of careful consideration of placement.